Forbidden Worlds was a 52 page comic with the initial subtitle "Exploring the supernatural!", debuted in October 1951. The comic was replaced by Young Heroes from February until October 1955, when it reappeared with #35 and the altered subtitle "Stories of strange adventure". #101 saw a price raise from 10 cents to 12 cents. From #108 on, it became sporadically two monthly instead of strictly monthly. #114 and #116 were special issues called Forbidden Worlds presents Herbie, featuring Herbie Popnecker, who was created in Forbidden Worlds #73 (December 1958). #125 to #138 all featured Magicman on the cover. The final issue was #145 (August 1967), when the company stopped producing newsstand comic books.